You can reset the color of materials, other than 3D objects, so the diffuse color no longer has any effect on the diffuse image.
If you reset the material color, depending on your preferences, the blending mode may also be changed. Resetting the material color automatically sets the blending mode to the mode specified in your preferences. For example, if the material blending mode is Multiply, and the default blending mode in your preferences is Overlay, when you rest the material color, its blending mode is changed to Overlay.
If the blending mode specified in your preferences is:
Multiply, the color resets to white
Overlay, the color resets to 50% gray
To reset the color of a trim item:
If the Materials tab is not already open, on the Resources tabs, click Materials.
Click the trim item you want to recolor.
Go to the Context view.
In the Diffuse part, click .